Buoyant plume above concentrated heat source in stratified porous media.

Buoyant plume arising from a point heat source and a line heat source in stratified porous media is investigated analytically and experimentally. First, a similarity solution, assuming the boundary layer approximation, is obtained for an inhomogeneous porous medium with variable permeability and thermal conductivity. Next, the analytical results are applied to the case of a porous system consisting of two horizontal porous sublayers with different permeabilities and thermal conductivities. Experiments are conducted on the temperature distributions and the variation in the width of the plume using a layered porous medium composed of water and two kinds of glass beads of different diameters. It is then found that the similarity solutions can considerably describe the development of the buoyant plume in the regions, except those near the interface. The vicinity of the interface is understood as a transition region of plume behaviors between the two similarity solutions.